This is tricky pls help!!

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

3.4a=57.8 what is the the value of a

The input to the function is x and the output is y. write the function such that x can be a vector (use element-by-element operations). a) use the function to calculate y(-1.5) and y(5). b) use the function to make a plot of the function y(x) for -2 ≤ x ≤ 6.